I'm all for stopping people but it's not like it's a major issue, we have the odd occurrence but that's it.
The odd occurrence isn't usually from new members who have signed up to scam. The username suggestion is not going to work.
Enforcing a pay only via paypal is backward
In my humble opinion, it is a case of using your common sense, paying by payal
(non-gift) or paying and collecting in person.